org.apache.hadoop.mapred.jobcontrol
Class Job

java.lang.Object
  org.apache.hadoop.mapred.jobcontrol.Job

public class Job
extends Object

This class encapsulates a MapReduce job and its dependency. It monitors the states of the depending jobs and updates the state of this job. A job starts in the WAITING state. If it does not have any depending jobs, or all of the depending jobs are in SUCCESS state, then the job state will become READY. If any depending jobs fail, the job will fail too. When in READY state, the job can be submitted to Hadoop for execution, with the state changing into RUNNING state. From RUNNING state, the job can get into SUCCESS or FAILED state, depending the status of the job execution.

Field Summary

static int	DEPENDENT_FAILED
static int	FAILED
static int	READY
static int	RUNNING
static int	SUCCESS
static int	WAITING

Constructor Summary

Job(JobConf jobConf)
Construct a job.

Job(JobConf jobConf, ArrayList<Job> dependingJobs)
Construct a job.

Method Summary

boolean	addDependingJob(Job dependingJob) Add a job to this jobs' dependency list.
JobID	getAssignedJobID()
ArrayList<Job>	getDependingJobs()
JobClient	getJobClient()
JobConf	getJobConf()
String	getJobID()
String	getJobName()
String	getMapredJobID() Deprecated. use getAssignedJobID() instead
String	getMessage()
int	getState()
boolean	isCompleted()
boolean	isReady()
void	setAssignedJobID(JobID mapredJobID) Set the mapred ID for this job as assigned by the mapred framework.
void	setJobConf(JobConf jobConf) Set the mapred job conf for this job.
void	setJobID(String id) Set the job ID for this job.
void	setJobName(String jobName) Set the job name for this job.
void	setMapredJobID(String mapredJobID) Deprecated. use setAssignedJobID(JobID) instead
void	setMessage(String message) Set the message for this job.
protected void	setState(int state) Set the state for this job.
protected void	submit() Submit this job to mapred.
String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

SUCCESS

public static final int SUCCESS

See Also:

Constant Field Values

WAITING

public static final int WAITING

See Also:

Constant Field Values

RUNNING

public static final int RUNNING

See Also:

Constant Field Values

READY

public static final int READY

See Also:

Constant Field Values

FAILED

public static final int FAILED

See Also:

Constant Field Values

DEPENDENT_FAILED

public static final int DEPENDENT_FAILED

See Also:

Constant Field Values

Constructor Detail

Job

public Job(JobConf jobConf,
           ArrayList<Job> dependingJobs)
    throws IOException

Construct a job.

Parameters:

jobConf - a mapred job configuration representing a job to be executed.

dependingJobs - an array of jobs the current job depends on

Throws:

IOException

Job

public Job(JobConf jobConf)
    throws IOException

Construct a job.

Parameters:

jobConf - mapred job configuration representing a job to be executed.

Throws:

IOException

Method Detail

toString

public String toString()

Overrides:

toString in class Object

getJobName

public String getJobName()

Returns:

the job name of this job

setJobName

public void setJobName(String jobName)

Set the job name for this job.

Parameters:

jobName - the job name

getJobID

public String getJobID()

Returns:

the job ID of this job assigned by JobControl

setJobID

public void setJobID(String id)

Set the job ID for this job.

Parameters:

id - the job ID

getMapredJobID

@Deprecated
public String getMapredJobID()

Deprecated. use getAssignedJobID() instead

Returns:

the mapred ID of this job

setMapredJobID

@Deprecated
public void setMapredJobID(String mapredJobID)

Deprecated. use setAssignedJobID(JobID) instead

Set the mapred ID for this job.

Parameters:

mapredJobID - the mapred job ID for this job.

getAssignedJobID

public JobID getAssignedJobID()

Returns:

the mapred ID of this job as assigned by the mapred framework.

setAssignedJobID

public void setAssignedJobID(JobID mapredJobID)

Set the mapred ID for this job as assigned by the mapred framework.

Parameters:

mapredJobID - the mapred job ID for this job.

getJobConf

public JobConf getJobConf()

Returns:

the mapred job conf of this job

setJobConf

public void setJobConf(JobConf jobConf)

Set the mapred job conf for this job.

Parameters:

jobConf - the mapred job conf for this job.

getState

public int getState()

Returns:

the state of this job

setState

protected void setState(int state)

Set the state for this job.

Parameters:

state - the new state for this job.

getMessage

public String getMessage()

Returns:

the message of this job

setMessage

public void setMessage(String message)

Set the message for this job.

Parameters:

message - the message for this job.

getJobClient

public JobClient getJobClient()

Returns:

the job client of this job

getDependingJobs

public ArrayList<Job> getDependingJobs()

Returns:

the depending jobs of this job

addDependingJob

public boolean addDependingJob(Job dependingJob)

Add a job to this jobs' dependency list. Dependent jobs can only be added while a Job is waiting to run, not during or afterwards.

Parameters:

dependingJob - Job that this Job depends on.

Returns:

true if the Job was added.

isCompleted

public boolean isCompleted()

Returns:

true if this job is in a complete state

isReady

public boolean isReady()

Returns:

true if this job is in READY state

submit

protected void submit()

Submit this job to mapred. The state becomes RUNNING if submission is successful, FAILED otherwise.